1. Field of the Invention
The invention is directed to a lockable piston-cylinder unit having a cylinder closed at both ends and filled with pressurized fluid in which a piston that is sealed relative to the inner wall of the cylinder is displaceably guided. The piston divides the interior of the cylinder into a first working chamber and a second working chamber and has a piston rod arranged at the piston and is guided out of the cylinder through one of the working chambers and through a guiding and sealing unit which closes the one end of the cylinder. An actuation rod is arranged to be axially displaceable, one end of the actuation rod projects out of the cylinder and can be acted upon by an actuation element so as to be movable in the push-in direction of the actuation rod, and a valve slide of a blocking valve which can be acted upon in closing direction by the pressure in the first working chamber can be acted upon by the other end of the actuation rod in opening direction of the blocking valve so as to be axially displaceable by a displacement between a closed neutral position and its open position, through which blocking valve the first working chamber can be connected to the second working chamber via a connection, wherein the actuation element is movable between an actuation position and a non-actuation position, and the actuation element contacts a stop in the non-actuation position.
2. Detailed Description of the Prior Art
In lockable piston-cylinder units of the type mentioned above, due to manufacturing tolerances, there is play between the actuation element and the actuation rod in the non-actuation position of the actuation element. Depending on the application, this play leads to rattling noises when these parts strike one another. To prevent a rattling noise of this kind, it is known to apply spring force to the actuation element in direction of the actuation rod so as to keep it permanently in contact with the actuation rod.
This arrangement is uneconomical and requires additional component parts and additional assembly effort.